91057871 has 4 divisors (see below), whose sum is σ = 91942032. Its totient is φ = 90173712.

The previous prime is 91057859. The next prime is 91057909. The reversal of 91057871 is 17875019.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17875019 = 109 ⋅163991.

It is a cyclic number.

It is not a de Polignac number, because 91057871 - 2⁶ = 91057807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91057171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 441926 + ... + 442131.

It is an arithmetic number, because the mean of its divisors is an integer number (22985508).

Almost surely, 2^91057871 is an apocalyptic number.

91057871 is a deficient number, since it is larger than the sum of its proper divisors (884161).

91057871 is a wasteful number, since it uses less digits than its factorization.

91057871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 884160.

The product of its (nonzero) digits is 17640, while the sum is 38.

The square root of 91057871 is about 9542.4247966646. The cubic root of 91057871 is about 449.8894724433.

The spelling of 91057871 in words is "ninety-one million, fifty-seven thousand, eight hundred seventy-one".